insomnia/app/ui/components/base/lazy.js

import {PureComponent, PropTypes} from 'react';
import autobind from 'autobind-decorator';

@autobind
class Lazy extends PureComponent {
  constructor (props) {
    super(props);
    this.state = {show: false};
  }

  show () {
    this.setState({show: true});
  }

  componentWillMount () {
    if (this.props.delay < 0) {
      // Show right away if negative delay passed
      this.show();
    } else {
      setTimeout(this.show, this.props.delay || 50);
    }
  }

  render () {
    return this.state.show ? this.props.children : null;
  }
}

Lazy.propTypes = {
  delay: PropTypes.number,
  children: PropTypes.node
};

export default Lazy;